Specific selection of immune cells using versatile display scaffolds

Abstract

Provided are compositions and methods for use in isolating cells responsive to a target protein by first contacting a collection of isolated cells in an in vitro sample to a complex and then isolating the complex. The complex is formed from a target protein with a capture tag coupled to a multimeric protein structure of at least two self-assembled copies of a monomeric protein substructure fused with a capture sequence.

1 . A method for isolating cells responsive to a target protein comprising:
 (a) contacting a collection of isolated cells in an in vitro sample to a complex, the complex comprising a target protein with a capture tag coupled to a multimeric protein structure of at least two self-assembled copies of a monomeric protein substructure fused with a capture sequence and optionally a linker and incubating therewith; and,   (b) isolating the complex.   
     
     
         2 . The method of  claim 1 , wherein the monomeric protein substructure is further fused with a complementary affinity sequence. 
     
     
         3 . The method of  claim 2 , wherein the complementary affinity sequence is a biotin tag. 
     
     
         4 . The method of  claim 2 , wherein step (b) is performed by introducing beads affixed with the complementary binding partner to the complementary affinity sequence and isolating the beads. 
     
     
         5 . The method of  claim 4 , wherein the complementary binding partner is avidin or streptavidin. 
     
     
         6 . The method of  claim 1 , further comprising before (b) incubating the complex with an antibody, wherein the antibody is biotinylated and binds to the monomeric protein substructure. 
     
     
         7 . The method of  claim 6 , wherein step (b) is performed by introducing beads affixed with avidin to the in vitro solution and isolating the beads. 
     
     
         8 . The method of  claim 4 , wherein the beads are magnetic. 
     
     
         9 . (canceled) 
     
     
         10 . The method of  claim 1 , wherein the monomeric protein substructure has at least 85% sequence identity with an amino acid selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 2 or SEQ ID NO: 3. 
     
     
         11 . The method of  claim 1 , wherein the capture sequence has at least 85% sequence identity with an amino acid selected from the group consisting of SEQ ID NO: 7, SEQ ID NO: 8 or SEQ ID NO: 9. 
     
     
         12 . The method of  claim 1 , wherein the monomeric protein substructure is further fused with a fluorophore. 
     
     
         13 . The method of  claim 12 , wherein the monomeric protein substructure has at least 85% sequence identity with an amino acid selected from the group consisting of SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18 or SEQ ID NO: 19. 
     
     
         14 . The method of  claim 1 , wherein the capture tag has at least 90% sequence identity with an amino acid selected from the group consisting of SEQ ID NO: 26 or SEQ ID NO: 27. 
     
     
         15 . The method of  claim 4 , further comprising isolating cells bound to the complex by flow cytometry. 
     
     
         16 . The method of  claim 1 , wherein the collection of cells comprise adaptive immune cells. 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . The method of  claim 1 , further comprising isolating nucleic acids from cells associated with the complex in (b). 
     
     
         20 . The method of  claim 1 , further comprising isolating a nucleic acid encoding an antibody after (b). 
     
     
         21 . (canceled) 
     
     
         22 . The method of  claim 1 , wherein the sample further comprises a second complex, the second complex featuring a second target protein different from the first. 
     
     
         23 . (canceled) 
     
     
         24 . A method for assaying a subject for immunity to a target protein comprising:
 (a) incubating a collection of cells isolated from the subject in an in vitro solution with a complex, the complex comprising a target protein with a capture tag coupled to a multimeric protein structure of at least two self-assembled copies of a monomeric protein substructure fused with a capture sequence and a linker and incubating therewith; and,   (b) measuring the complex and analyzing for associated proteins.   
     
     
         25 . A method for preparing a B cell in vitro tissue culture with binding affinity to a target protein comprising:
 (a) incubating a collection of cells comprised of B cells in an in vitro solution with a complex, the complex comprising a target protein with a capture tag coupled to a multimeric protein structure of at least two self-assembled copies of a monomeric protein substructure fused with a capture sequence and a linker and incubating therewith;   (b) isolating the complex;   (c) isolating B cells from the complex; and   (d) transferring isolated B cells from (c) to a tissue culture medium.   
     
     
         26 .- 51 . (canceled)